We are studying 1) tissue-specific neuropeptide expression and 2) regulation of neuropeptide biosynthesis and secretion in developing and mature neuroendocrine cells. We would like to understand how second messenger systems activated by neurotransmitters and electrical activity converge on the regulatory elements of neuropeptide genes to effect the establishment of neuropeptide phenotypes during development, and affect the rates of neuropeptide secretion and gene transcription in normal and pathophysiolgocial states.